Control mechanism



Dec. 8, 1931. M. 1.. STRAWN- 1,334,986

CONTROL MECHANISM Filed Jan. 28, 1928' 2 SheetSeSheet 1 Dec. 8, 1931. M.1.. STRAWN CONTROL MECHANISM Filed Jan. 28. 1928 2 Sheets-Sheet 2Patented Dec. 8, 1931 UNITED STATES PATENT! OFFICE MARION LLEWLLYNSTRAWN, OF CHICAGO, ILLINOIS, ASSIGNOR '1O WESTERN ELEC- TRIC COMPANY,INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OI NEW YORK CONTROLMECHANISM Application filed January 28, 1928. Serial No. 250,325.

- table adapted to be raised manual y by the usual hand lever, there isprovided a high pressure fluid medium circulating system whoseeffectiveness may be varied to raise the table. The effectiveness of thefluid pressure medium is controlled through the operation of thecustomary lever, which when resistance to the movement of the table isencountered is operated with greater force, and the effectiveness of thepressure medium is likewise increased for supplying sufficient energy toovercome the resistance. Thus the operator is aided in raising thetable, but its movement is always under the operators control throughthe actuation of the lever, as the force of the pressure medium on thetable is several times greater than the pressure applied to the lever.The flow of the medium through the system and the control thereof foroperating the drill press is such that it lends itself to the connectionin parallel of a group of drill presses in a single'circulating system.

Other objects and advantages of this invention will more fully appearfrom the following detailed description taken in connecti on with theaccompanying drawings, wherein Fig. 1 is a fragmentary side view of amultiple spindle drill press with one embodiment ofthe control mechanismof this invention applled thereto for operating the work table thereofFig. 2 is a fragmentary side view thereof of an enlarged scale;

Fig. 3 is a front view of Fig. 2 looking toward the right thereof;

Fig. 4 is an enlarged vertical section'taken on the line 4-4 of Fig. 3,and

Fig. 5 is a schematic illustration of a group of drill press tables,each equipped with the control mechanism of this invention and suppliedwith a pressure medium from a common constant high pressure source.

Referrin now to the drawings in detail wherein 1i e reference numeralsindicate similar parts, particularly Fig. 1, which illustrates amultiple s indle drill ress rovided with one embodiment of theinvention, a base supports a vertical frame 11 u on which the entiremechanism of the multi Ie spindle drill press is mounted. A work ta le12 is secured to an apron 13, the latter being slidable in ears 14 whichare fixed to the frame 11 whereby whatever material is placed upon thetable 12 may be brou ht into contact with drills 15 carried from a ead16. The drills 15 may be operated in any suitable manner, the details ofwhich are not shown since they are not believed necessary to a completeunderstanding of this invention.

The table 12, referring particularly to Fig. 2-, is raised by theactuation of a gear and crank mechanism by the movement of a hand leverfixed to a pivotal arm 21, a valve assembly to be presently referred toforming an operative interconnection between the lever and the ear andcrank mechanism. The arm 21 is ree to pivot upon a bearing boss 22,shown in dotted outline Fig. 2, formed upon a rocking plate 23 in turnfree to pivot on. a stud shaft 24. Attached to the plate 23 is a gearsegment 27 which meshes with a gear 28 keyed to a' shaft 29 supported inspaced bearings 30 (Figs. 2 and 3). Keyed to the shaft 29 intermediatethe bearings 30 is a lever 31 pivotally connected at its free end to thelower end of a link 32 shown in dotted outline in Figs. 2 and 3, theupper end of the link being pivotally connected to a pin 33 adjustablyclamped to the apron 13. It will be apparent that upon the gear seggear28, shaft 29 and attached lever 31 will be revolved clockwise, therebycausing the -ment 27 being rocked counter-clockwise the link 32, pin 33and the attached apron 13 to by an intermediate length of flexible ipe63 move upwardly, thus the work table 12 will connected to a main supplyl1ne 64 1g.

, be raised. while the casing chamber 60 1s connected Secured to theplate 23 below the arm 21 through an outlet port 67 which connected byscrews 34 is a valve 35. Referring parto the inlet port of the supplysource by a ticularlyto Fig. 4 the valve 35 comprises an flexibletransmission pipe 68 connected to a 70 onter supporting casing 36.The-casin 36 main return line 69 ig. 5%. The chamber upon its rear orleft side, as viewed in ig- 61 is provided with a ort Oservmg alter- 3,is provided with a tongue 37 which has a natel as an outlet an mlet portin the op- 10 sliding fit in a. longitudinal groove 38 formed r tion" fthe control mechamsm to be de- 5 in the adjacent surface of the plate 2A scribed hereinafter. An inelastic ressure plurality of threadedapertures 39 are formed medium such as oil may be. used with very in theplate 23 along the groove 38 into which d lt the screws 34 may bethreaded so h the Secured to the outer-surfaces of the ears 15 valve maybe secured at any one of a plu- 14 upon hich the a ron 13 slides isa U-rality of selectable points, the pur ose of h d strap 71 (Fig. 3), alower horizontal which will be made apparent as this eso parm 74 ofwhich is positioned adjacent the tion progresses. Sec r x ly wlhhln alower surface of the apron when the latter chamber 40 of the casing 36 ia bushmg is in its normal or lowered position. To the g0 provided alongits length with thr llIllfront surface of the apron 13 is secured aformly Spaced Sets of Ports 43 and threaded rod 75 which freely extendseach Set pif iciii iihiiciihiy p e through a bridge piece 76 extendingbetween P The icwei end of the ng 41 is and integral with the lower pairof ears 14. q pp with an cuiwaidiy extending Threaded onto the rod 75 ateach side of 111113! P which is p against an the bridge piece 76 arenuts-or stop collars 9o nular surface formed in the casing 36 by a 77,hi h it ill b apparent may b dj tl 45 Screw threaded into an aperture inthe ed to predeterminedly limit the movement iOWeI' end of the casihg-Mounted in a e of the apron 13 and consequently the table 12' 4 her 46extending ichgitiidiheii ig the either in an upward or downwarddirection.

3 bushing 41 is a Valve Piston 4 Provided at Fixed to the lower surfaceof the horizontal 95 its upper end with a stem 48 WhlCh extends arm 74fth Strap 71 i a pressure di through an aperture in the pp epdef thefeed cylinder 78 provided with a piston 81, casing 36 and intoengagement with a hat a stem or rod 82 thereof extending throughhorizontal surface 51 formed upon the underh arm hi h serves as a h d tclose one 3 Side of h 'h the arm Testing y the end of the cylinder 78,the opposite end therewe action of Q hof being closed by a head 83. Aclosed flex- The Piston is provided h e c ible transmission line 84connects the port 52 along its longitudinal axis, which s closed 70 f thl i h b 1 ith th at each end. The diameter of the plston 47 li d 7 anaperture 5 b i o id d at its lower end is g y less than its pp in thelower head 83 for the entrance of the 105 end and his a correspondinglySmaller P pressure medium within the cylinder and lien oi the chamber 46cf the bushing against the lower surface of the piston 81. the Purposeof which will become PP i' In the normal position'of the drill press theas this description p g The P B piston 81 is maintained in-its loweredosi- 45 eral surface of the piston 47 is formed w th ti as shown i -Fi 3b th i ht 0 th PP and ihwei' ahiiuiel' g forming table 12 and the apron13, the lower end surehembels 53 and p y, the lower face of the ,apronat all times engaging the chamber. being of considerably greater upper df th i t d 32, i h h hlength than the upper chamber so that it tio thupper t p llar 77 engages the may interconnect the ports 43 and 44 ofthe mid e piece 76, no appreciable pressure ochi g 4 in'the 1101111111 ps n of the P curring between the apron and the piston rod. ton as shownin the drawings, the purpose of The operation of the drill press hereindewhich will be described hereinafter. A plurib d embodying the controlmechanism of rality of uniformly spaced ports 55 and 56 this inventionis as follows: With the parts 55 are formed in the piston 47 which serveto in the position shown in the drawings, par- 1 interconnect thechambers 53 and 54 of the ti l rl Fi 3 l 4, ,nd ith th i piston 47 withthe axial chamber 52 thereof. ply line 64 connected to a suitable means(not Formed in the inner circular Wall of the casshown) for en plying aconstant high presing chamber 40 are three annular grooves or. surefluid medium thereto, the medium flows cc chambers 59, 60 and 61 withwhich the ports from the line 64 through the pipe 63 in the i" 42, 43and 44 communicate respectively at direction indicated by the arrows,the valve all times. The casing chamber 59 is concasing chamber 59, thebushing inlet ports 42, nected through an inlet port 62 with theoutwhich are slightly open, the piston chamber let port of a suitableconstant, high fluid 53,.returning through the piston ports 56, the

" pressure medium supply source (not shown)v piston chamber 54,'thebushing outlet 'ports 43, which are slightly open, the casing chamber60, the pipe 68 to the return line 69 and back to the source of supply.This is the normal condition, the medium passing through the restrictedinlet and outlet ports 42 and 43, respectively, to solely provide for avery small circulation ofthe medium to prevent sticking of the piston47, and thence through the bushing ports 44, casing chamber 61 and pipe84 to the cylinder 78. Due to the greater area of the annular surface ofthe piston 47 at the upper end of the chamber 54 compared to the lesserdiameter at its lower end caused by the difference in diameter of thepiston along its length, an unbalanced condition exists in the valve 35,thus the pressure medium will normally exert sufiicient pressure on thepiston to maintain the stem 48 thereof up against the surface 51 of thearm 21. An adjustable weight 86 is carried on the hand lever 20 so thatthe downward pressure of the arm 21 against the upper end of the piston47 will be equal to the pressure of the mediumand that created by theweight of the cylinder piston 81 transmitted upward upon the valvepiston 47 through the intervening medium, thus a balancing of the forceson opposite sides of the piston 47 occurs. Upon downward pressure beingapplied to the hand lever 20 this balance is overcome, the inlet ports42 of the interconnecting valve 35 are thereby opened and the outletports 43 are closed. A variable flow of the medium in the system is thuscreated and the increased back pressure of the medium is immediatelyexerted on the piston 81 of the cylinder 78 which assists the operatorin raising the table 12. It is, of course, understood that the manualforce exerted by the operator in depressing the lever 20 to operate thevalve is also applied as a portion of the total force required to liftthe table 12, through the movement of the entire lever assembly whichincludes the arm 21 and the plate 23 which function as a single leverpivoting on the shaft 24 and through the segment 27 attached to theplate 23 and associatedmechanism hereinb'efore. described transmitsmotion to the table.

The manual effort required to raise the table 12 and to complete thedrilling operation is thus materially reduced, since only sufiicientdownward pressure is required on v the hand lever 20 to maintain theinlet ports 42 open. The resistance to the upward movement 'of the table12 and the consequent engagement of the drills with the work willimmediately and positively be evident to the operator by the increasedback pressure created in the line which acts to move the valve piston 47upwardly against the pressure exerted by the operator on the hand lever20. In the case of the first condition when the operator feels thisupward thrust on the lever 20 from the valve piston 47 he increases hispressure downward on the lever in proportion to the upward pressurethereon, thus maintaining the inlet ports 42 open and the upwardmovement of the table 12 continues. In the case of the latter conditionhe merely releases the pressure on the lever 20 and raises it. Upon theoperator releasing the pressure on the hand lever 20 the drill press andcontrol mechanism will remain in the position to which they have beenoperated when the lever is released due to the balanced forces acting onopposite sides of the piston 47 as hereinbefore described. The raisingof the hand lever 20 closes ports 42 and opens the ports 43 to theirfull sfze, thus the back pressure in the closed pipe 84 to the cylinder78 is released and the weight of the press table 12 forces the mediumfrom the cylinder through the pipe 84, the casing chamber 61, bushingports 44, piston chamber 54, and through the outlet ports 43, theoperating parts of the drill press and control mecha-- nism movingdownwardly to their normal position as shown in Fig. 3. One'of theprincipal advantages of this invention is that the operator can feel atall times the behavior of the drills 15 on the work. This is of greatadvantage, because when the normal progress of the drills are interferedwith, or if the operator feels in his hand'that the drills are throughthe work being drilled, he can immediately either further lower the handlever or release his pressure thereon and raise it in accordance withthe condition encountered. The lower stop collars 77 are preferablyadjusted on the rod 75 so that they engage the lower surface of thebridge piece 76 when the desired movement of the work carried by thetable 12 relative to the drills 15 is accomplished. As hereinbeforedescribed this condition is immediately indicated to the operator, whoreleases the hand lever 20 and raises it relative to the plate 23 andthus the ports 42 and 43 are opened to their normal size, the table 12being lowered.

The ratio of the. force applied by the operator to the hand lever 20 andthe pressure of the medium on the feed cylinder piston 81 can be varied,it will be apparent, by

changing the position of the valve 35 with I respect to the axis of thearm 21. In the drawings the adjustment is such that a maximum handpressure is required on the lever 20 to cause the table 12 to beelevated. To reduce this pressure the screws 34 are removed from theapertures 39 and the valve assembly 35 is moved along the groove 38 ofthe plate 23 and closer to the pivotal point of the arm 21, which is theshaft 24, and rebolted in position by threading the screws into anotherpair of apertures.

Fig. 5 illustrates schematically a group of drill press tables, eachequipped with the control mechanism hereinbefore described and eachconnected to a common high pressur fluid medium circulating system,comprising supply and return lines 64 and 69,

- group of the control mechanisms with out effooting the other controlmechanisms connected in a similar manner to the same high pressuremedium circulating system, or that all of the press tables may beoperated simultaneously.

One of the outstanding advantages of the control mechanism hereinbeforedescribed resides in its facile adaptability to commercial types ofdrill presses without making extensive alterations therein.

Although the invention has been disclosed and described as applied to aparticular type of apparatus, it is clear that it may have a moregeneral application and that modifications canbe made without departingfrom the spirit and scope of the appended claims.

What is claimed-is:

1. In, a mechanism for controlling the movement of a power responsivebody, manually operable means directly connected with the body throughgear mechanism for moving the body, a fluid pressure medium circulatingsystem having means connected thereto also operable for moving the body,a valve controlled by a movement of the manually operable means forcausing the medium operable means to act upon the body in accordancewith the manual force. applied to the manually operable means, saidvalve includin a piston reciprocably mounted therein having a stembearing against the manually operable means, and means for allowing thepressure medium normally circulating through the easing andthe pistonand acting on the latter to maintain the stem thereof inoperative engagement with the manually operable means at all times.

2. Ina mechanism for actuating a work table, manually operable meansincluding gear mechanism for preliminarily moving the work table, and afluid pressure system also..for moving the table and assisting themanually operablemeans therein, said fluid pressure system including apiston connected to the work table, a cylinder for actuating the piston,a valve connected with the manually operable means for directingpressure from the fluid pressure system against the piston uponapredetermined movement of the manually operable means to furtheractuate the work table, the fluid pressure system otherwise beingdisconnected from the.

piston, and means in the valve responsive to the pressure of the fluidpressure system for normally maintaining the valve closed.

In witness whereof, I hereunto subscribe my name this 19 day of JanuaryA. D., 1928.

MARION LLEWLLYN STRAWN.

